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    <title>ShellCheck: SC2080 – Numbers with leading 0 are considered octal.</title>
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    <h1>SC2080 – ShellCheck Wiki</h1>
    <a href="https://github.com/koalaman/shellcheck/wiki/SC2080">See this page on GitHub</a>
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    <h2 id="numbers-with-leading-0-are-considered-octal">Numbers with
leading 0 are considered octal.</h2>
<h3 id="problematic-code">Problematic code:</h3>
<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="SC2080.html#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="bu">echo</span> <span class="va">$((</span> <span class="dv">16</span> <span class="op">-</span> <span class="dv">08</span> <span class="va">))</span></span></code></pre></div>
<h3 id="correct-code">Correct code:</h3>
<div class="sourceCode" id="cb2"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb2-1"><a href="SC2080.html#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="bu">echo</span> <span class="va">$((</span> <span class="dv">16</span> <span class="op">-</span> <span class="dv">8</span> <span class="va">))</span></span></code></pre></div>
<h3 id="rationale">Rationale:</h3>
<p>ShellCheck found an integer literal with a leading zero, but
containing the digits 8 or 9.</p>
<p>This is invalid, as the integer will be interpreted as an octal value
(e.g. 0777 == 0x1FF == 511).</p>
<p>To have the value parsed in base 10, either remove the leading zeros
as in the example, or specify the radix explicitly:</p>
<pre><code>echo $((10#08)) </code></pre>
<h3 id="exceptions">Exceptions:</h3>
<p>None</p>
<h3 id="related-resources">Related resources:</h3>
<ul>
<li>Help by adding links to BashFAQ, StackOverflow, man pages, POSIX,
etc!</li>
</ul>
<p><a
href="https://www.gnu.org/software/bash/manual/html_node/Shell-Arithmetic.html">The
BASH manual "Shell Arithmetic" chapter</a></p>
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    <p style='font-size: 80%'><a href="../index.html">ShellCheck</a> is a static analysis tool for shell scripts. This page is part of its documentation.</p>
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